I guess the only person that knows the answer to that is him. Maybe he truly values your friendship, or maybe there is more to it than that. But it shows how loyal you are to consider his new girlfriends feelings above how much you enjoy being his friend. I guess the question is, does his new girlfriend know how much the two of you talk? If not, There are most likely more complicated feelings involved. Maybe make it clear where you stand, even if you have to sneakly drop things like ‘Thanks, you’re such a great friend’ in conversations to see his response. If this still doesn’t solve it, maybe take a step back & if he persists, ask him straight out where you stand. Goodluck!